1. The Field of the Invention
The present invention relates to valves, and, in particular, relates to hemostasis valves. More particularly, the invention relates to an adjustable hemostasis valve having a quick-release mechanism.
2. Relevant Technology
Several current surgical procedures require temporary and often repeated introduction of catheters and/or guidewires into the cardiovascular system of a patient. For example, using only a relatively small incision, a catheter can be introduced into the body of a patient and used to deliver fluid, such as medication, directly to a predetermined location within the cardiovascular system. Catheters can also be used for exploratory surgery and for removing tissue samples within a body. One increasingly common use for catheters is in the placement of small balloons which can be selectively inflated within a blood vessel. The balloons are used for opening blood vessels that have been blocked or partially blocked by plaque build-up. This opening or altering of the vein is referred to as angioplasty.
A common catheter design used in performing many of the procedures includes an elongated, flexible, cylindrical catheter body having a fluid flow passageway or a lumen extending along the interior of that catheter body. During one type of use, an end of the catheter is inserted into the body of the patient through an incision in a blood vessel in the cardiovascular system. The catheter is advanced along the internal passageway of the vessel until the end of the catheter is located at a desired predetermined location for conducting and intended activity.
A guidewire is a long, cylindrical, flexible wire that is commonly used for directing the catheter to the desired location within the body. A guidewire is typically smaller in diameter and more rigid than a catheter. It is, therefore, easier for a surgeon to first direct and advance a catheter within the cardiovascular system to the desired location within the body of the patient. The opposing end of the guidewire, positioned outside the body of the patient, is then received within the lumen of the catheter. Using the guidewire as a guide, the catheter is advanced along the length of the guidewire so as to properly position the catheter within the body of the patient. If desired, the guidewire can then be removed from within the catheter to open the lumen of the catheter. In an alternative process for inserting the catheter, the guidewire is initially received within the lumen of the catheter and the catheter and guidewire are simultaneously advanced within the cardiovascular system of the patient.
Operations using catheters can often require the insertion and removal of several different types of catheters and guidewires. One of the problems encountered with the insertion and removal of catheters and guidewires is controlling bleeding at the point where the catheters and guidewires are first introduced into the cardiovascular system.
In one approach to controlling bleeding and insuring easy insertion and removal of the catheter and/or guidewire within the cardiovascular system, one end of an introducer is first secured within a large vein of a patient. An introducer is a relatively large, hollow tube. The opposite end of the introducer is positioned outside the body of the patient and is attached to an adapter.
An adapter typically comprises a short, rigid tube having a passageway extending therethrough. Attached at one end of the adapter tube is a connector. The connector is used to connect the passageway of the adapter to the exposed end of the introducer. This enables fluids and/or medical instruments, such as catheters and guidewires, to pass between the adapter and the introducer.
Positioned at the opposite end of the adapter tube is a valve commonly referred to as a valve apparatus. The valve apparatus includes an enlarged chamber portion at the end of the adapter remote from the patient. The chamber is aligned with and is connected to the passageway extending through the adapter. Positioned within the chamber is some type of seal. During use of the adapter, the pressure of the blood causes blood from the patient to flow up through the introducer and into the passageway of the adapter tube. The seal, which either closes independently or is compressed around the catheter or guidewire, restricts blood from spilling out of the adapter through the access of the valve.
Various seal arrangements are available with different types of valve apparatus ranging from one seal to a plurality of seals. One of the main purposes of the valve arrangement is to be able to block off the passageway to stop the loss of bodily fluids from the valve apparatus. One type of seal that has been used in valve apparatus is a soft, cylindrical, compressible seal. The compressible seal has a passageway extending along the length of the seal. The seal is oriented in the chamber so that the passageway in the seal is aligned with and connected to the passage in the adapter tube.
To seal the valve apparatus that incorporates a compressible seal, a portion of the valve apparatus is advanced, typically a shaft, which in turn compresses the seal within the chamber. Compression of the seal causes the passageway in the compressible seal to constrict. If the shaft is advanced sufficiently far within the chamber, the passageway in the seal constricts so as to form a seal around the exterior surface of the catheter or guidewire positioned in the passageway. Alternatively, if the catheter or guidewire is removed from within the seal, the passageway in the seal can constrict in response to compression force so that the seal completely closes off the access through the valve.
Current designs that utilize compressible seals require the compressive force to be removed from the compressive seal in order to remove the catheter or guidewire from the valve apparatus. Removing the compression force often required rotating the end portion of the valve apparatus or some other way of incrementally removing the force. The present methods of removing the force take some amount of time which results in a needless loss of blood and increases the risk of contamination of the blood of the patient. It is important to be able to quickly make adjustments or insert/remove the guidewire or catheter without unnecessary time passing. Furthermore, leaking bodily fluids, including blood, may produce both a messy and slippery work environment for the surgeons. With the increasing number of blood disorders such as AIDS, blood leakage from the adapter increases the risk to the surgeon and other medical personnel.
Attempts have been made to solve the leakage problem by making valve apparatus that utilize two or more seals. Typical seals include duck-bill valves and slit valves. While multiple seals in the valve apparatus are useful in helping to reduce the loss of body fluids, including blood, several problems still exist. Current valve apparatus, regardless of whether the valve has one or two seals, generally have an open position and a closed or sealed position. Once the valve apparatus is closed, the surgeon is not able to move or reposition the catheter or guidewire without putting the valve apparatus into the open position where body fluids can flow out the valve. For example, if the valve utilizes a compressible seal, the catheter or guidewire cannot be repositioned or removed unless substantially all of the compressive force is removed from the compressible seal. Once the compression force is removed, the valve apparatus is no longer sealed. The available valve apparatus are not configured to provide a seal against a loss of bodily fluids while still allowing the catheter or guidewire within the valve to be repositioned.
An additional problem with existing valve apparatus is that the seals, and in particular those seals that are compressed to form a seal, tend to exert a force upon the catheter or guidewire. The forces, including the frictional forces acting on the instrument, are commonly referred to as "drag." The drag acting on the catheter or guidewire disposed in a seal makes it difficult for the surgeon to be able to adjust the catheter or guidewire. In particular, it is very difficult to be able to adjust the catheter or guidewire by the "feel" of the movement. Currently, the valve apparatus must be adjusted to remove the compression forces acting on the seal. Removing the compression forces acting on the seal results in fluid leakage.
Finally, having to remove the compression force, reposition or remove the catheter or guidewire, and then readjust the valve apparatus to compress the seal so as to form a seal is time consuming and in turn unnecessarily lengthens the procedure.
It will be desirable to have a valve apparatus that can be quickly opened and closed to reposition or remove a catheter or guidewire without having to remove the compression forces and is able to minimize blood leakage from the valve apparatus, or reset the desired amount of drag acting upon the guidewire or catheter. It would also be advantageous to have a valve apparatus in which the seal will remain sealed but will allow an instrument such as a catheter or guidewire to be longitudinally repositioned without exerting so much drag on the catheter or the guidewire that the surgeon is unable to have a feel for the movement of the guidewire or catheter.